Management of IgG subclass deficiency in adults

An intact immune system is essential for prevention of injury from infectious microorganisms, toxins, tumor cells, and autoimmunity. The importance of antibodies is clearly demonstrated by the recurrent acute infections in patients with antibody deficiency syndromes. IgG, the major immune globulin in serum, is composed of 4 subclasses, and each has its own properties. Although some patients with deficiencies of 1 or more of the IgG subclasses have recurrent infections, others are healthy. This has led to controversies over the clinical significance of IgG subclass deficiencies and their relationship to susceptibility to recurrent infections.